The CFAR Molecular Virology/Virology Core serves as a foundational support and important resource for AIDS investigators at AECOM and collaborating institutions. The technologic repertoire of the Core includes both quality-controlled routine and specialized HIV-1 methodologies, including (1) Molecular cloning and prorogation of HIV-1 isolates (2) Determination of acid-labile and acid-stable HIV-1 p24 antigen concentration; (3) HIV culture [Qualitative, Quantitative, Plasma, Tropism-Variant]; (4) HIV isolation and concentration; and (5) HIV neutralization. The Core has demonstrated ability and capacity for efficiently handling a large and diverse research and clinical specimen load, as reflected in its virologic support of numerous AECOM investigators as well as multiple ACTG sites. In addition, Core personnel encompass a brad range of expertise and experience in the field of retrovirology, with recognized contributions in HIV-1 research, forming an effective framework for stimulation of interactive multidisciplinary collaborations. These assets have enabled the Core to actively support research directed toward HIV-1 vaccine development, investigation of maternal-feta transmission of HIV, efficacy of therapeutic interventions in HIV disease, development of novel modalities for prevention of HIV-1 transmission via blood-products, research on the role of viral variants in maternal-fetal HIV transmission, evaluation of viral load in HIV- infected patients in clinical trials, and variety of additional basic and clinical AIDS-related research projects and clinical applications. The CFAR Virology Core provides access to state-of-the-art technologic support and to Core personnel having current scientifically sound expertise and experience in HIV-1 retrovirology, and thus furnishes an environment which promotes interactive, collaborative research and facilitates timely application of basic research to the clinical arena.